ML17223A518

LER 90-001-00:on 900114,steam Generator Feed Pump 2B Low Suction Pressure Alarm Received,Condensate Pump 2A Would Not Start & Pump B Tripped on Low Suction Pressure.Caused by Personnel Error.Pump Governor Oil drained.W/900213 Ltr

ML17223A518
Person / Time
Site:	Saint Lucie
Issue date:	02/13/1990
From:	Sager D, Weeks J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-90-60, LER-90-001-01, NUDOCS 9002230298
Download: ML17223A518 (6)

Text

AC%.ELERATIK) DISIBUTION DEMONSIKOION SYSFEM I

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR: 9002230298 DOC. DATE: 90/02/13 NOTARIZED: NO DOCKET FACIL:50-389 St. Lucie Plant,- Unit 2, Florida Power & Light Co. 05000389 AUTH. NAME AUTHOR:AFFILIATION WEEKS,J.W. Florida Power & Light Co.

)

SAGER,D.A. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-001-00:on 900114,automatic reactor trip on low steam generator water level during power ascension.

W/8 DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report (LER), Incide ENCL t Rpt,SIZE:etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 . 1 PD2-2 PD 1 1 NORRIS,J 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2. 2 ACRS WYLIE 1 1 AEOD/DOA '1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 . 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 ~ 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NR~R'J)ST/SPLB8D1 1 1 NRR/DST/SRXB 1 1 G

GN2 FIT~FEZ 01 02 1 1

1 1

8E'ES/DSIR/EIB 1 1 EXTERNAL: EG&G WILLIAMS,S 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NVIKTO ALL "RIDS" RECIPIENIS'LEASE HELP US TO REDUCE WASIEl CONI'ACT THE DOCUMENT CONIROL DESK, ROOM Pl-37 (EXT. 20079) 70 ELIMINA'IEYOUR NAME FROM DISTIGBVHON LISIS FOR DOCUMENIS YOU DEPT NEE&l FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 37 ENCL 37

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P.O. Box 14000,Juno Beach, FL 33408 0420 APL FEBRUARY. i3 1990 L-90-60 10 CFR 50-73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: St. Lucie Unit 2 Docket No. 50-389 Reportable Event: 90-01 Date of Event: January 14, 1990 Automatic Reactor Trip On Low Steam

, Generator Water Level During Power Ascens'on Due To Personnel Error The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, D. A. ager Vice P esident St. L cie Plant DAS/GRM/rh Attachment cc: Stewart D. Ebneter, Regional Administrator, Region Senior Resident Inspector, USNRC, St. Lucie Plant II, USNRC 90022 '0298 9002i3 PDR ADOCK 0 000389 PDC an ppL Group companY

FPL Facsiniro ol U.S. NUCLEAR REGULATORY COMMISSION NRC Form 366 APP ROVED 0M B NO. 31600104 (8.83) LlCENSEE EVENT REPORT (LER) EXPIRES Sr31rm FACILITYNAME (1) DOCKET NUMBER (2)

ST. LUCIE, UNIT 2 05000389103 AUTOMATICREACTOR TRIP ON LOW STEAM GENERATOR WATER LEVEL DURING POWER ASCENSION DUE TO PERSONNEL ERROR EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

MONTH DAY YEAR YEAR MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

N/A 05000 0 1 1 4 9 0 9 0 0 0 1 0 0 2 1 3 9 0 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR:

Check one or more of the follo in 11 MODE (9) 20.402(b) 20.405(c) X 50.73(a)(2)(iv) 73.71(b)

POWER LEVEL

'0.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c)

(10) 0 5 0 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER 20.405(a)(1) (ili) Specify in Abstract 50.73(a) (2)(l) 50.73(a)(2)(vill)(A) below and in Text 20.405(a) (1)(iv) 50.73(a)(2) (ii) 50.73(a)(2)(viii)(B) NRC Form 366A) 20.405(a)(1)(v) 50.73(a)(2)(iil) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER (12)

NAME JAY W. WEEKS, SHIFT TECHNICAL ADVISOR AREA CODE 4 0 7 465-3550 B A COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 CAUSE SYSTEM COMPONENT MANUIC- REPORTABLE 6 5 2 9 0 TO NPRDS CAUSE SYSTEM COMPONENT ~+II I R/PO+TQBLE REPORT EXPECTED 14

'UPPLEMENTAL EXPECTED SUBMISSION YES (Ifyes, complete EXPECTED SUBMISSION DATE) NO DATE (15)

ABSTRACT (Limit to $ 400 spaces. I.e. approximately fifteen single-space typewritten lines)(1 6)

On 14 January, 1990, St. Lucie Unit 2 was in Mode 1 and performing power ascension towards 100% power following a reactor startup from a maintenance outage. The turbine startup procedure was being utilized. The 2B Steam Generator Feed Pump and 2B Condensate Pump were in service. Reactor power was approaching 50% with the turbine power increasing at 4.0 Megawatts per minute when the 2B Steam Generator Feed Pump low suction pressure alarm was received. Utility licensed operators attempted to start the 2A Condensate Pump but it would not start. The 2B Steam Generator Feed Pump tripped on low suction pressure. The pump was unable to be restarted. The Steam Generator water levels decreased to the automatic trip setpoint and the unit automatically tripped at 2325. The 2C AuxiliaryFeedwater Pump tripped on overspeed upon receiving an AuxiliaryFeedwater Actuation Signal. Standard Post Trip Actions were performed and the unit was stabilized in Mode 3.

The second condensate pump could not be started prior to the trip because its control fuses had not been re-installed following outage work. Procedures have been changed to ensure the availability of the second condensate and feedwater pump further in advance of being needed and to clarify the power ascension procedure. The 2C Auxiliary Feedwater Pump was returned to service. A cognitive personnel e'rror by the utility licensed operators led to the automatic reactor trip.

ocsrm 0 NRC Form 368 t8-83)

F PL Facoirrilo ol UB. NUCLEAR REGULATORY COMMISSION NRC Form 3M LICE E EVENT REPORT (LER) TEXT CONTINUA ON APP ROVEO OM B NO. 31500104 (0.83) EXPIRES 8/31/85 FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

ST. LUCIE, UNIT2 YEAR SEQ IITIAL REVlglP 0 5 0 0 0 3 8 9 9 0 0 0 1 0 0 0 2 0 3 TEXT (Ifmore spaceis required, use additional NRC Form 366A's)(17)

On 14 January, 1990, St. Lucie Unit 2 was in Mode I and performing a power ascension on the Main Turbine (EIIS:TA) after starting up from a maintenance outage. Main Turbine power was being increased with the Digital Electro-Hydraulic (EIIS:TG) (DEH) rate at 4.0 Megawatts per minute. The 2B Condensate (EIIS:SD)

Pump and 2B Steam Generator Feed Pump (EIIS:S J) (SGFP) were running.

During the power ascension, and prior to the trip, a problem was encountered with the 'A'oisture Separator Rehcater (EIIS:SB) (MSR) Block Valve. While the problem was being investigated, the turbine power increase was continued. The block valve was subsequently made operable and opened. The MSRs were then begun to be placed in service. Reactor thermal power was approximately 45% at this point. While the MSRs were being placed in service, the 2B SGFP low suction pressure audible annunciator (EIIS:IB) alarm was received. An attempt was made to start the 2A Condensate pump. The control fuses for the 2A Condensate pump were not installed, and the pump would not start. While the fuses were being installed, the 2B SGFP tripped on low suction pressure. The turbine power ascension was stopped. The 2B SGFP was restarted, but tripped again. The fuses were installed in the 2A Condensate pump control circuit and an attempt was made to start the pump, but the pump failed to start because the switch was not held in the start position for a sufficient-amount of time. The 2B SGFP was restarted two more times but tripped on low suction pressure both times.

At 2325 the Steam Generator (EIIS:AB) (SG) low water level trip signal to the Reactor Protective System (EIIS:JC) was received and the unit automatically tripped while at 50% rated thermal power. The 2C Auxiliary Feedwater (EIIS:BA) (AFW) turbine driven pump automatically started upon receiving the Auxiliary Feedwater Actuation Signal (EIIS:JE) (AFAS) on low SG water level but tripped due to overspeeding. The 2A and 2B motor-driven AFW pumps started and supplied flow to both SGs. The turbine tripped on a reactor trip signal.

Standard Post Trip Actions were performed and thc unit was stabilized in Mode 3.

FT F T'he root cause of the event was cognitive personnel error by not closely following the approved turbine startup procedure. Utilitylicensed operators were behind in the turbine startup procedure for the particular power level. The condensate and feedwater system is capable of supplying only 50% feedwater flow with one condensate pump and one SGFP running. When the unit reached 50% power the running SGFP lost suction pressure. There were no unusual characteristics in the Control Room at the time of the event.

Contributing factor to this event is:

The 2B SGFP low suction pressure trip switch was found to be set approximately 40 pounds per square inch higher than normal which caused the pump to trip sooner than it would normally.

NRC Form 388 18.83)

FPL FscsiniIo oI U.S. NUCLEAR REGULATORY COMMISSION NRC Form 368 APPROVED OMB NO. 3153013l (0-83) LICENSEE EVENT REPORT (LER) TEXT CONTINUATION EXPIRES 131/85 FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR REVISIgl ST. LUCIE, UNIT 2 0 5 0 0 0 3 8 9 9 0 0 0 1 0 0 0 3 0 3 TEXT(lfmore space is required, use additlorial NRC Form 366A's)(17)

The plant response during this trip was observed to be normal; all systems functioned as designed with the exception of the 2C AFW pump which tripped on overspeed. The 2A and 2B AFW pumps, each with 100%

capacity, started and supplied fiow to both SGs.

'his event was reportable to the NRC under 10CFR50.73(a)(2)(iv) as any event or condition that results in an automatic actuation of the Reactor Protection System.

This event was bounded by that described in Section 152.5.1.1 of the Unit 2 FUSAR, which assumes a loss of feedwatcr by means of a feedwater pipe rupture. The actual plant response was much more conservative to that described in the analysis for several reasons: 1) The plant was not at full power when the event occurred.

2) AFW flow was initiated by thc AFAS signal in approximately 210 seconds as opposed to the 420 seconds considered in the accident analysis. 3) Neither SG had thc water level go below 48% Wide Range, therefore, the capability of the SGs to act as a primary heat sink was never in jeopardy.

Thus, the health and safety of the public was not endangered at any time during this event.

RF.

1. The Nuclear Plant Supervisor and Assistant Nuclear Plant Supervisor were counseled by the Operations Supervisor on attention to detail.

2. OP 2-00301%, Turbine Startup Zero to Full Load procedure has been revised to clarify when to place a second condensate and fecdwatcr pump in service.

3. The 2B SGFP low suction pressure trip switch has been reset to the correct trip setpoint.

4. The 2C AFW pump overspeed trip has been investigated. It was found to have foreign matter in the turbine .

governor hydraulic oil. A preventative maintenance schedule is being implemented to comply with the manufacturer's recommendation for changing the pump governor oil to ensure this event is not repeated. The 2C AFW pump governor oil was drained, flushed, and the pump was extensively retested.

The pump was returned to service.

il m nn I ifi 'n 2C AFW pump turbine governor, Model No. PG-PL Woodward Governor Company vi imil rEv The following LERs describe similar low SG level trips at St. Lucie:

335-89-003 335-88-008 389-86-010 L scsrmie NRC Form 366 IQ-83)

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